print("this is module3.py file")

# 设置可以被其他模块导入的函数
__all__ = ["add","subtraction","multiplication","division","test"]

def add():
    print("this is add function")

def subtraction():
    print("this is subtraction function")

def multiplication():
    print("this is subtraction function")

def division():
    print("this is division function")

def test():
    print("this is test function")